Radioisotope induced X-ray fluorescence analysis is a rather simple and convenient method for investigating ashed plant material.
In order to reduce matrix effects, thin samples (2 mg/cm2) are analyzed to obtain a reasonable compromise between maximum sensitivity and the lowest possible absorption effects. Concentrations
are determined by standard addition method. A precision of 6–8% can be achieved. As an application, analytical results are
given for whole grains of several sorts of wheat.
The adsorption kinetics of strontium ion was studied on seven natural clay samples with radioactive tracer method. The kinetic
curves were determined and the kinetic data were evaluated by forms of first-rate kinetic equations with different terms,
generally used for adsorption of ions of low concentration. The adsorption process was reduced to two steps. Film diffusion
and participle diffusion were found in the case of five samples. Gel diffusion, film diffusion and participle diffusion were
found in the case of the other two samples. The presence of significant amount of cristobalite can explain the gel phase in
these two samples. The rate coefficients of steps were calculated from the kinetic curves.
Authors:Á. Nagy, J. Bogáncs, J. Gyulai, A. Csőke, V. Nazarov, Z. Seres, A. Szabo, and Yu. Yazvitsky
A measuring technique based on the alpha particles being released from the10B(n, α) nuclear reaction and using the time-of-flight technique at a periodically pulsing reactor was developed. Non-destructive
determination for the range distribution of boron impurities in ion-implanted silicon have been performed. Projected ranges
obtained in the energy region 20–80 keV are compared to calculated results and to other experiments. Examples are shown for
some typical boron distributions before and after annealing the sample.
Authors:E. Kuzmann, S. Stichleutner, Z. Homonnay, A. Vértes, A. Paszternák, F. Nagy, I. Felhősi, G. Pető, J. Telegdi, and E. Kálmán
Thin films prepared by vacuum evaporation of 57Fe and subsequent low energy ion implantation were investigated by conversion electron Mössbauer spectroscopy and AFM measurements.
A sextet with Mössbauer parameters of δ = 0.1 mm/s and B = 26 T appearing in the CEM spectra was identified as amorphous iron. Passivation and phosphonation of the thin films revealed
the high affinity of amorphous iron in chemical reactions.